Model based water management diagnosis in polymer electrolyte membrane fuel cell

Water management diagnosis in polymer electrolyte membrane fuel cell is of great importance. The water produced in the fuel cell affects its performance and lifetime through the current distribution and the two phase flow pattern in the channel. The aim of the present study is to modify a segmented model in order to investigate a model-based water management diagnosis at different operating conditions. Simulations are conducted in three current densities: low (0.2 A/cm2), medium (0.6 A/cm2) and high (1 A/cm2), four temperatures ranged from 40 to 70, two stoichiometries (2 and 3) and four inlet humidities (25%, 50%,75% and 100%). The results show that at fully saturation inlet condition, there is a uniform local current density for all three considered current densities. Also, two-phase pressure drop and output voltage have similar trends. Hence two phase pressure drop can be considered as a suitable criterion for water management diagnosis. At inlet humidities less than 50%, non-uniformity of local current density increases that leads to reduction of output voltage, especially at high current density. Generally, for non-saturated inlet condition, two phase pressure drop and output voltage may show different trends. Therefore, two-phase pressure drop can be used only as a criterion for the formation of water and not for water management diagnosis. •A modified segmented model for water management diagnosis in PEMFC is illustrated.•Fuel cell performance and flow regime in channel is studied simultaneously.•Pressure drop is as a criteria in diagnosis only at inlet saturated condition.•Flow regime is main factor in water management diagnosis at low current density.